I have edited this a bit to make it clearer. I really would like to know from someone out there whether there is a real regulatory issue here as I find the literature pretty impenetrable for the layman. I am concerned that my house insurance might be undermined and I am concerned about real problems in the case of a house fire!

I have plastic gas pipes laid under the house to supply a gas fire. These are sheathed in larger plastic pipes - which seems to be OK from a reg. point of view. These plastic pipes (painted to disguise them, I think) are connected by a steel connector (which is busily rusting) attached to the house at a metre above ground level to narrower copper gas pipes leading to the meter and the street supply.

I am being told that all of this is a no-no and that I must have the supply to the gas fire (on the opposite side of the house to the meter) re-piped in copper passed through the roofspace and the under-house pipes disconnected. Is this right? The house was diy built in the 90's.

Hi
Plastic can not be used after the meter. This needs to be re piped in copper. The route depends on how much you want to pay. You can run the pipe in the screed on the floor or under the floorboards if you have wooden floors, but it does need to be protected if in screed. Get a gas safe registered engineer out and they will be able to update it to current regs.

^^ Both of these are suitable for running on the consumer side of an installation.

I would strongly advise you seek professional advice; if someone has run the gas pipework in plastic; you will be entitled for that person to pay to put it right; afterall - Even a DIY build in the 90's must comply with the Gas Safety Installation & Use Regulations; and plastic pipe has never been permitted for use internally.

I am installing a new natural gas water heater in my home. The existing gas line to the old heater is black pipe to rigid copper pipe to a short piece of flexible copper tubing terminated in a 1/2" flared connector. Can 1/2 ' black pipe from the new water heater be connected directly to the copper flex tube or should there be a dielectric union separating the 2 disimilar metals? Would it be better to remove all the copper pipe and tubing and just install black pipe all the way to the water heater?

RobertChella, I would initially say no. It sounds like the existing flexible copper tube would have been supplied with the old water heater an could be installed as per that appliances manufacturers specifications.

With issues like this, I always chop out and start again. Any time I have to question myself I always go for the safest option. It might add an hour onto the job but I can leave with a clear conscience.